A number of technologies exist to monitor critical infrastructure such as electrical grids. Most of these systems include wire-based voltage and current sensors, which rely on inductive and capacitive sensors for monitoring the level of voltage or current. The voltage and current sensors are then coupled to associated data processing units that are required to convert the measured inductance and/or capacitance to the voltage or current values measured by the sensors. The sensors are connected to the associated data processing units via copper wires. These wire-based monitoring systems have a number of limitations. For example, wire-based systems suffer from issues of reliability, are not as accurate as newer sensors (i.e., accuracy is approximately +/−2%), and the measurement accuracy can be affected by fluctuations in temperature. For example, signal transmitted long distances over copper wire can be degraded.
Other grid monitoring technologies that address the problems with wire-based systems include wireless monitoring technologies. These wireless monitoring systems clamp onto power line cables and harvest energy for operation directly from the lines. Unlike the wire-based monitoring technologies, the wireless monitoring systems that monitor voltage and current do not send data via copper wires, but instead rely on wireless communications, such as cellular signals. The wireless sensors used in wireless condition monitoring for electrical grids also suffer from limitations in reliability. By way of example, wireless transmission requires that the sensor incorporate electronics that are sensitive to electro-magnetic fields very near a strong electromagnetic field, which can impact the overall reliability of such systems.
Optical sensors provide a third type of technology for monitoring electrical grids. Optical sensors provide a number of advantages over wire-based and wireless monitoring systems. By way of example, optical sensors provide greater accuracy, better reliability, and easier methods for temperature compensation. Unlike wire-based and wireless technologies, optical sensors rely on analog optical telemetry for transmission of data. Analog optical telemetry offers a number of advantages relative to copper wires and wireless data transmission. For example, the optical signals do not suffer significant degradation of the signal when transmitted over long distances in the same manner as copper wire. Additional, optical systems do not require sensors including electronics that are sensitive to electro-magnetic fields very near a strong electromagnetic field, such as in electrical grids. While analog telemetry offers advantages over these other signal transmission methods, it can suffer to impairment due to connection quality.
Impairments in analog optical telemetry may occur due things such as the condition of optical components, contamination, moisture, or operator errors. The impairment can lead to optical losses that lead to inaccurate data and lost information, which can have major impacts on critical infrastructure, such as electrical grids.
The present technology is directed to overcoming these and other deficiencies in the art of analog optical telemetry.